A man who was strangled and dismembered at a flat in Deptford before his daughter was also killed was a sex offender, police say.

Noel Brown, 69, and his daughter Marie, 41, died in his southeast London flat on Monday.

Police believe there is a "strong possibility" that Marie disturbed the attackers as they tried to dismember Mr Brown's body.

Detectives have revealed that Mr Brown was given a four-year jail sentence for a sex offence in 1999, but say the conviction was not "screaming out" as a motive for his murder.

Detective superintendent Paul Monk said: "The offence was a sex offence, he was convicted and served time and was released in 2004 but I'm not prepared to give any more details."

Forensic examinations have been carried out at the home on New Butt Lane, Deptford, and hours of CCTV footage is being studied.

Police have appealed to the public for help and are keen to speak to two men who visited Mr Brown's flat in the days before he was found dead.

Image:Mr Brown's daughter Marie was also murdered

So far no evidence has been found to support a theory that Mr Brown was killed because of a large gambling win, although he did visit a local Paddy Power betting shop on the last day he was seen alive.

No sign of a break-in was found and there were no indications of a struggle inside the flat or that Mr Brown had been restrained.

Mr Monk said: "One of our key lines of inquiry is to establish if the suspect or suspects were known to Noel and if Marie disturbed them.

"One of the key strands of our investigation is understanding all we can about Noel's life.

"He was well known and liked locally. There has been speculation that his murder was as a result of a large gambling win.

"However, at this time there is no evidence to suggest this was the case."

Mr Monk said Mr Brown's biggest win was thought to be up to £15 or £20.

Appealing for help from the public, he added: "One of the possibilities I'm investigating is that these people were known to Noel so I'm particularly keen to hear from anybody that knew Noel, knew his lifestyle and knew people he may associate with.